1. Field of the Invention
The invention relates to a method of generating a field map automatically in a video game, and in particular, a method of generating more natural geographical features by transforming a selected quadrilateral automatically.
2. Description of the Related Art
In recent years, video game devices have spread to many families quickly. And there are various types of game, such as a role-playing game, a simulation game, a combat game, a puzzle game, and the like.
In a typical role-playing game, dungeon is often used. In the game, treasure or items which are necessary for the game may be hidden in the dungeon, or a strong monster may appear from the dungeon.
Herein, the dungeon generally means "labyrinth" in an actual game. Therefore, the dungeon may be expressed as land, a natural cave, an ice cave, or a lava cave. In such a game, a video game character (for example, main character) moves in the dungeon and therein, encounters various items and monsters, as a story of the game proceeds. Of course, the story varies according to selection of loads or response to encountering of the items or monsters. In this specification, image data representing whole geographical features which are used as the dungeon are referred to as a "field map".
In general, it is necessary to prepare many patterns of shapes of the dungeon (for example, shapes of land) so that a user of the game does not lose interest in the game. To this end, when the game is started or at the other timing, a shape of the dungeon is automatically generated, for example, by using a random number.
However, in the prior game, a shape of the dungeon which is automatically generated becomes unnatural shape since the dungeon is generated by combining a plurality of quadrilaterals. For example, even if the dungeon expresses land or a cave, a boundary of the dungeon, that is, a boundary line between the land and the sea surrounding the dungeon is not generated in a natural and complex shape.
In other words, the boundary line is formed as a shape of steps, that is, a shape with coarse notches in the prior game. Due to the limitation of expression, natural and complex geographical features are not fully represented. Therefore, when a story of the game proceeds on a nature, it is not possible to communicate to a user of the game a feeling of open-air or refreshment, as a result, it is not possible to give the user a feeling of being at a live performance.